Imagine having a bicycle with a closed chain guard. One day the chain falls off & you realize it's assembled with tamper-proof screws.
Now imagine the manufacturer wanting to make unscrewing that screw a felony carrying a 5-year prison sentence & a $500K fine.
They'd be booed out of business, if not institutionalized.
None the less, that's EXACTLY how DMCA 1201 works.
Despite @pluralistic & others' efforts I feel this isn't clear to the general public.